Method of peripheral indicia-molding



Oct. 18, 1955 E. DANIELSON ETAL 2,720,681

METHOD OF PERIPHERAL INDICIA-MOLDING 5 Sheets-Sheet l JNVENTORS E [.MEP DANIELSON Biz OY D J- D ill]:

F??? June 1 1951 OF SEN TTORNEYS 1955 E. DANIELSON ETAL 2,720,681

METHOD OF PERIPHERAL INDICIA-MOLDING Filed June 1, 1951 5 Sheets-Sheet 3 INVENTORS ELMER L DAN! ELS'ON F LOYD J. DOFSE N BY A'r-rdRN EYS Oct. 18, 1955 E. L. DANIELSON ETAL ,7 0, 81

METHOD OF PERIPHERAL INDICIA-MOLDING Filed June 1, 1951 5 Sheets-Sheet 4 mi d wm ATTORNEYS Oct. 18, 1955 E. DANIELSON ETAL 2,720,631

METHOD OF PERIPHERAL INDICIA-MOLDING Filed June 1, 1951 5 Sheets-Sheet 5 7g 14. f 35 a 5% F INVENTORS m: 7/2 ELMER L DANIELSON LOYD J- DOF'SEN ATTORNEYS United States Patent Ofiice 2,720,681 METHOD DF PERTPHERAL INDICIA-MOLDING Elmer L. Danielson, Qak'iand, and Floyd J. Dofsen, San

Francisco, Calif., assignors to Elmer L. Danielson, Gal:- land, and Floyd J. Dofsen, San Francisco, Calif, as joint tenants Application June 1, 1951, Serial No. 229,478 6 Claims. (Cl. 1859) The present invention relates to improvements in a method of peripheral indicia-molding. it consists of the steps of the method. More specifically, this invention has reference to an improved method of molding numerals, or other appropriate indicia, on peripheral surfaces of counterwheels, or other articles.

As the cardinal object of our invention, we provide a relatively simple and inexpensive method of rapidly molding indicia on peripheral surfaces, for instance, on counterwheels. The indicia thus produced is made in a selected color giving proper contrast with the surface on which it is arranged. Even though the article is used over an extended period of time, under rather severe wearing conditions, the indicia will remain distinct with clear outlines.

Briefly stated, our method includes the precasting of a strip of plastic material having indicia-conforming slots extending therethrough between opposing surfaces of the strip. Thereafter, this strip is bent, or curved, into a predetermined shape corresponding with the configuration of the desired periphery of the completed article. While the strip is maintained in this shape, material of a contrasting color is cast in such a manner as to fill the slots of the strip, with this material flowing to and being exposed on a preselected surface of the strip. The material for this subsequent casting may provide the body of a counterwheel, for instance, although we do not wish to be limited in this respect.

Various shapes of precast strips may be provided, depending upon the configuration of the peripheral surface in the final article. For example, a straight strip may be rolled into a. loop when the peripheral surface of a counterwheel is to be made cylindrical; while a precast curved strip is adapted to be formed into a truncated cone for use on a tapered peripheral surface of another completed article. In any event, a simple set of dies may be employed for casting the article in its final form.

Other objects and advantages will appear as the speci fication continues. The novel features of our invention will be set forth in the claims hereunto appended.

DRAWINGS For a better understanding of the invention, reference should be had to the accompanying drawings, forming part of this application, in which:

Figure l is a plan view of a precast straight strip having indicia-conforming slots extending therethrough between opposing faces of the stri Figures 2 and 3 are transverse and longitudinal sectional views taken along the planes iI-II and TIL-iii, respectively, of Figure 1;

Figure 4 is a face view i lustrating as being curved into a cylindrical loop;

Figure 5 is a vertical sectional view, partly in elevation, and discloses this looped strip after it has been placed in an annular bore of a removable mold plate, the latter being associated with a lower die;

Figure 6 is a View similar to Figure 5, but continues this precast strip 2,720,681 Patented Oct. 18, 1955 the casting process, and shows an upper die closed against the lower die; moreover, it illustrates the casting of the indicia-forming material with the completed article being disclosed in section;

Figure 7 is a vertical sectional view taken through the completed article and the removable plate, the latter having been removed from the lower die;

Figure 8 is a vertical axial sectional view taken through the first embodiment of the completed article, this view being taken along the plane VIIIVIlI of Figure 9;

Figures 9 and 10 are opposing face views of the finished article as seen from the right and left sides, respectively, of Figure 8;

Figure 11 is an elevational drical peripheral surface pleted article;

Figure 12 is a vertical sectional view, with parts in elevation, and discloses a modified form of a completed article, in which indicia is provided on a truncated conicalshaped peripheral surface;

Figure 13 is a vertical sectional view taken through the modified article and the removable plate of the lower die;

Figure 14 is a front elevational view of the modified article, looking at the indicia-carrying face thereof;

Figure 15 is a vertical sectional view taken along the plane XV-XV of Figure 14;

Figure 16 is a face view of a curved strip, which is utilized for providing the indicia on the second form of our article; and

Figure 17 is a transverse sectional the line XVII-XVII of Figure 16.

While we have shown only the preferred forms of our invention, it should be understood that various changes, or modifications, may be made within the scope of the annexed claims without departing from the spirit thereof.

DETAILED DESCRIPTION view observing the cylinof the first form of the comview taken along First form Referring to the embodiment of our invention as shown in Figures 1 to 11, inclusive, it will be noted that we provide a precast strip designated generally at A. In actual practice, this strip is made from thermoplastic material, and is provided with a plurality of indicia-conforming slots B extending therethrough between the opposing outer and inner faces 10 and As disclosed in Figure merals 0 and 9, indicia, as used herein, any discriminating mark, or design. Although it cation proceeds that the 11, respectively, of the strip.

1, the slots B define the nuinclusive. However, the term is sufliciently generic to include sign, letter, character, symbol will be apparent as the specifistrips A are intended to be used on counterwheels, we do not desire any limitation in this respect; accordingly, broad interpretation is intended of the expression indicia-conforming slots.

It will be apparent that the numerals 0, 4, 6, 8 and 9 define island-like portions 12, which are surrounded by the slots. These portions are supported in the plane of the web 14 of the strip by bridging elements 15. The sectional view in Figure 2 illustrates these elements as being spaced below the outer face 10 of the precast strip so that they will be concealed when the slots are filled subsequently by plastic material forming a second part or member C.

The strip A is channel-shaped in cross-section, and defines parallel marginal flanges 16 projecting from its web 14 on the inner face 11. These flanges straddle the slots B, and prevent the strip from breaking in the regions of the slots when the strip is bent or curved into a closed loop, as shown in Figure 4. When the strip is thus curved, its opposing ends 17 are brought into abutting relation with one another to form the strip into a cylindrical configuration, with the flanges 16 extending inwardly of the cylinder. Better results will be obtained in curving the strip, if the latter is slightly warm before commencing the curving thereof.

In actual practice, the strip A occupies this cylindrical configuration and is held in that shape while thermoplastic material for the second part or member C is cast against the inner face 11, or peripheral surface, of the looped strip (see Figures '6 to 8, inclusive).

Next, we shall describe the dies that we employ for casting or injecting the material for the second part C. In Figure 5, a lower die D has been illustrated as having a main cylindrical core 18 secured thereto so as to project above its top surface 19. This core has an axiallydisposed core 20 fixed therein to extend above the top 21 of the main core.

Furthermore, we provide a removable plate E having an annular bore 22 extending downwardly thereinto from the top 23 thereof. This plate is fashioned with a cylindrical opening 24, which extends from the bottom ledge 25 of the bore 22 to the underneath surface 26 of the removable plate. The opening 24 is dimensioned for snug telescoping over the main core 18 until the plate E comes to rest on the top surface 19 .of the lower die D.

In Figure 5, we show the ledge 25 as being spaced below the top 23 of the plate E at a distance equal to the width of the web 14 of the strip A. Accordingly, the lowermost flange of this strip will rest on the ledge 25, while its uppermost flange is disposed flush with the top 23 of the removable plate.

Turning now to Figure 6, we disclose an upper die F having a bottom face 27 adapted to be brought down against the top 23 of the removable plate E. Also, this same face is adapted to abut the top end of the axial core 20 when the upper die is closed upon the removable plate.

The thermoplastic material for the second part or member C is injected through channels 28 in the upper die F so as to fill the unoccupied space of the bore 22 in the plate E. This incoming material is injected against the inner peripheral face 11 of the strip A and fills the indicia-conforming slots B. This will produce indicia G on the completed article, which is exposed to view on the outer peripheral surface 10 of the completed article (see Figures 8 and 11). Also, the channel 11a of the strip A will be filled with the incoming indiciaforming material, and the latter will embed the flanges 16 therein.

The spacing of the top 21 of the main core 18 below the bottom face 27 of the upper die F will produce a disc 29 in the final product. opening 30 formed therein by the axial core 20.

After the injection for the second part or member C has been completed, the upper die F is raised. At this time, ejecting pins 31 are raised in a conventional manner until the plate E is removed from the cores 18 and 21?.

Figure 7 illustrates the plate E after its removal, while still supporting the completed article. The latter may be taken out of the bore 22 very easily, and the sprues 32 broken therefrom.

SUMMARY OF OPERATION First form It will be understood, of course, that the lower and upper dies D and F, respectively, are mounted in an injection machine in the usual way. The operator disposes the looped strip A in the annular 'bore 22 of the plate E so that the flanges '16 of this strip will extend inwardly relative to the loop.

With the upper and lower dies arranged in separated relation with one another, the plate E and its looped strip A are depressed around the main core 18 until the underneath surface 26 of this plate is supported on the top 19 of the lower die, as in Figure 5.

Now the upper die F is brought down'into contact with This disc has a central the top 23 of the removable plate E, as suggested in Figure 6. Accordingly, an annular space is provided between the main core 18 and the inner peripheral surface 11 of the looped strip A. Moreover, a space is left between the top 21 of the main core and the bottom face 27 of the upper die F. These spaces are shown in Figure 5 of the drawing.

The incoming thermoplastic material for the second part C, or member, is injected into the channels 28 for flow into the unoccupied space around the cores 1S and 21 This material will fill the indicia-conforming slots B of the precast strip A, flowing to the outer peripheral surface 10 of the strip. Moreover, the channel 11a will be filled by the injected material, and at the same time the disc 29 of the member C will be formed.

After this injected material has set, the upper die F is elevated, and the plate E, together with the completed article, are removed from the lower die and its cores (see Figure 7). Now the operator withdraws the article from the plate E, and at a convenient time the sprues 32 are removed.

Of course, dies may be provided having a number of cavities therein, thus allowing a plurality of articles to e cast during each operation. This is conventional pract re, and will speed up the production.

The precast strip A may be made of any suitable color, and the member C fashioned from material giving a contrasting color. Inasmuch as the indicia G extends through the entire thickness of the strip A, the indicia will maintain sharp outlines, even though the article may be subjected to considerable wear. The flanges 16 not only prevent the strip A from breaking in the regions of the slots B; but preclude the sharp angular bending of the strip, thereby promoting uniform curving thereof.

DETAILED DESCRIPTION Second form The second embodiment of our invention is illustrated in Figures 12 to 17, inclusive. Whereas the first form provides for molding indicia on a cylindrical peripheral surface, our second form relates to providing indicia on a truncated conical-shaped surface. The steps of the method of the two embodiments are quite similar and follow the same general pattern.

Reference is made to Figures 16 and 17, wherein we have shown a precast curved strip H. This strip is made of such a length as to extend completely around the truncated conical-shaped peripheral surface I in the final article (see Figures 14 and 15), with the opposing ends 33 of the strip arranged in abutting relation with one another.

As in the first embodiment, the precast strip H is made of thermoplastic material, and is provided with a plurality of indicia-conforming slots K disposed in a curved row, which extend between the inner and outer faces of the strip. Of course, these slots may be arranged so that the indicia can be read from a desired direction. Again, we have disclosed the numerals O to 9, inclusive, by way of illustration, but we are not to be limited in this regard.

This precast strip is channel-shaped in cross-section, as clearly shown in Figure 17. It includes a web 34 having marginal flanges 35 projecting from the inner periphery thereof in straddling relation with the indiciaconforming slots. It is quite apparent that this strip may be curved or fashioned into a truncated conical-shaped configuration, especially when the strip is slightly warm. The flanges 35 preclude the strip from breaking in the regions of the slots K during the curving of the strip, preventing the sharp creasing of the strip; and aiding in producing uniform curving of the latter.

In Figure 12, we illustrate a lower die L having a removable plate M mounted thereon, and an upper die N. It Will be noted that the lower die has a main core 36 secured thereto so as to project thereabove into a cylindrical opening 37 provided in the plate M. A truncated conical-shaped bore 38 is provided in this plate and it converges downwardly to and merges into the opening 37. This tapered bore is shaped to receive and support the outer periphery of the truncated conicalshaped strip H, with the lowermost flange of the latter resting on a bevelled upper edge 39 of the main core 36. It will be observed that an axially-disposed core 40 is carried by the main core so as to project thereabove.

In its structural features, the upper die N includes a core 41 fixed thereto, which is provided with a frustoconical projection 42 on its underneath face. This projection is adapted to be partially inserted into the bore 38 of the plate M when the bottom 42' of the upper die contacts with the top 43 of this plate, as in Figure 12. Moreover, the core 41 is formed with a counterbore 44, which is adapted to receive the axially-disposed core 40. The top of the latter bears against the bottom wall 45 of the counterbore when the die N and plate M bear against one another.

Thus the upper die N and the plate M coact to define a space in which a second part or member P is cast from thermoplastic material. As shown, the member P constitutes the body for a counterwheel, although other suitable objects could be made within the spirit of this invention. The material for the second part P is made of a color contrasting with the precast strip.

The material for the second part P is delivered through channels 46 to the unoccupied space between plate M and the cores 36, 40 and 41. This incoming injection of material will flow against the inner peripheral surface of the truncated conical-shaped precast strip H, filling the channel of the strip and the indiciaconforming slots K, providing indicia Q. The latter are exposed on the tapered peripheral surface J of the final product. The core 40 provides a bore 47 in the hub 48 of the counterwheel.

After the thermoplastic material for the body of the counterwheel has set, the upper die N is retracted. Thereupon, ejecting pins 49 are raised so as to remove the plate M and the final article from the cores 36 and 40. Now the article may be withdrawn from the plate M and the sprues 50 severed therefrom.

SUMMARY OF OPERATION Second form Assuming that the plate M is disposed on the lower die L in the manner shown in Figure 12, and that a truncated conical-shaped precast strip H is supported on the seat provided by the tapered bore 38 and the core 36, the operator depresses the upper die N into contact with the plate M.

Now the operator causes an injection of thermoplastic material through the channels 46 so as to completely fill the unoccupied space defined by the plate M and the cores 36, 40 and 41. This will produce the second part or member P, with the indicia Q filling the slots K. This indicia is exposed on the truncated conical-shaped periphery J of the counterwheel.

After raising the upper die N out of the way, ing pins 49 are actuated to remove the plate M from the cores 36 and 40 (see Figure 13). The plate will carry the completed article therewith, which may be readily removed from this plate. Removal of the sprues 50 may be accomplished at any convenient time. Multiplecavity dies may be utilized for simultaneously casting several counterwheels, or other objects.

As in the first embodiment, the indicia Q extend entirely through the thickness of the precast strip H. This indicia will not become obliterated by wear or dirt.

We claim:

1. in the herein described method of peripheral indicia molding, the steps of precasting a substantially fiat and the ejectflexible strip with at least one indicia conforming slot extending therein beneath a first surface thereof and communicating with a second surface opposite said first surface, subsequently bending said strip into a substantially predetermined shape and inserting the strip into a mold having a surface predetermining the final shape of the strip, the resiliency of the strip causing said first surface to contact with the mold surface, and thereafter forcing indicia forming material against said second surface and filling said slot therewith with said material extending to and being parallel with said first surface while the strip is maintained in said predetermined shape.

2. In the herein described method of peripheral indicia molding, the steps of precasting a substantially fiat and flexible strip with at least one indicia conforming slot extending therein beneath a first surface thereof and communicating with a second surface opposite said first surface, subsequently bending said strip into a substantially predetermined shape in the form of a continuous closed loop with opposite ends of the strip arranged in substantially abutting relation with each other and the looped strip presenting inner and outer peripheral surfaces With said first surface forming said outer surface and inserting the strip into a mold having a surface predetermining the final shape of the stri the resiliency of the strip causing said first surface to contact with said molding surface and to assume a predetermined shape of a continuous closed cup.

3. In the herein described method of peripheral indicia molding, the steps of precasting a substantially fiat and flexible strip with at least one indicia conforming slot extending therein beneath a first surface thereof and communicating with a second surface opposite said first surface, subsequently forming said strip into a substantially predetermined shape of a loop with the looped strip presenting outer and inner peripheral surfaces with said first surface forming said outer surface and positioning the strip into a mold having a surface predetermining the final shape of the strip, the resiliency of the strip causing said first surface to contact with said molding surface.

4. In the herein described method of peripheral indicia molding, the steps of precasting a substantially fiat and flexible strip with a channel shaped cross section to define a Web having spaced apart flanges extending lengthwise of said strip and projecting therefrom with at least one indicia forming slot extending into said strip beneath a first surface thereof and communicating with a second surface opposite said first surface, subsequently bending said strip into a substantially predetermined shape and inserting the strip into a mold having a surface predetermining the final shape of the strip, the resiliency of the strip causing said first surface to contact with the mold surface, and thereafter forcing indicia forming material against said second surface and filling said slot theresaid predetermined shape.

5. In the herein described method of peripheral indicia molding, the steps of precasting a substantially fiat and flexible strip with a plurality of spaced indicia conforming slots arranged in a row and disposed at a predetermined distance from one another and extending into said strip beneath a first surface thereof and communicating with a second surface opposite said first surface, subsequently bending said strip into a substantially predetermined shape and inserting the strip into a mold having a surface predetermining the final shape of the strip, the resiliency of the strip causing said first surface to contact with the mold surface, and thereafter forcing indicia forming material against said second surface and filling said slot therewith with said material extending to and being parallel with said first surface while the strip is maintained in said predetermined shape.

6. In the herein described method of peripheral indicia molding, the steps of precasting a substantially fiat and flexible strip which is curved along its length and provided with'at least one ,indicia conforming slot extending therein beneath a first surface thereof and communicating with a second surface opposite said first surface, subsequently bending said strip into a substantially predetermined shape of atruncated core, the core presenting inner and outer peripheral surfaces between which the slot extends and inserting said strip into a mold having a surface predetermining the final shape of the strip, which surface is in the shape of a truncated core, the resiliency of the strip causing said first surface to contact the mold surface and thereafter forcing indicia forming material against said second surface and filling said slot therewith with material extending to and being parallel with said first surface while the strip is maintained in said predetermined shape.

References Cited in the file of this patent UNITED STATES PATENTS 130,140 Judson Aug. 6, 1872 1,889,179 Lobl Nov. 29, 1932 1,989,676 Bodle Feb. 5, 1935 2,001,491 Hendey May 14, 1935 2,288,187 Gits June 30, 1942 2,298,364 Gits Oct. 13, 1942 2,361,139 White et al. Oct. 24, 1944 2,432,870 Evalt Dec. 16, 1947 2,565,803 Danielson et al. Aug. 28, 1951 

